Electric vulcanizing device



Nov. 14, 1939. A. H-OVING 2,179,819

ELECTRIC VULCANIZ'ING DEVICE Filed Dec. 23, 1936 s Sheets-Sheet 1 nveni'or 3 Sheets-Sheet 2 nveni'or Nov. 14, 1939. A. HOVING ELECTRIC VULCANIZING DEVICE Filed Dec. 23. 1936 W n n n I I I n n IIIIIIIIIIIIIIIII l l l '1 Nov. 14, 1939. A. HOVING 2,179,819

Qnvenkor Patented Nov. 14, 1939 UNITED STATES PATENT OFFICE Application December 23, 1936, Serial No. 117,302 In Canada January 13, 1936 1 Claim.

sure that such produced heat will be concentrated 5 on the exact area required to be treated, and at the same time to provide means so that the device will withstand the pressure necessary in the process of vulcanization, it beingfully realized that previous inventions have included elections have been applied in practice in a manner much less satisfactory than would be the case with my invention.

I attain these objects by the mechanism illustrated in the accompanying drawings, in which- Fig. 1 is a view of the complete electrical element vulcanizing pad.

Fig. 2 is a detail in large scale of the branch element in section marked A in Fig. 1.

Fig. 3 is a similar detail of branch element in section B in Fig. 1.

Fig. 4 is a similar detail of branch element in section C in Fig. 1.

Fig. 5 is a longitudinal section of the main ribbon flexible element container of the pad.

Fig. 6 is a cross section of the vulcanizing trough, tire, and pressure applying mechanism.

Fig. 7 is a cross section of the tube repair arrangement of flexible elements.

Fig. 8 is a perspective of a part of element protective plate .with grooves.

Fig. 9 is a part section of pressure block for driving toggle bars.

Fig. 10 is a plan view of the selector plug switch.

Fig. 11 is a plan view of the current regulator.

Similar numerals refer to similar parts throughout the several views.

In the drawings the numeral I represents as a whole an electrical element container in the form of a pad. This pad consists of a series of elongated saw-tooth shaped branches 2 projecting from the sides of the flat ribbon central portion trical elements applied on one side only -,ofthe, "1 material to be vulcanized, and that said in'venlof pad seen as 3. The branches 2 are shaped as stated in order to accommodate the circumferential curvature of the tire around which the said pad is disposed for'vulcanizing purposes, and so assist in the closing together of the said projecting branches 2. Electric conducting wires 4 are enclosed within the said pad and its branches 2, such wires forming a circuit with the wires in the opposite branches and those in the ribbon container 3. Feed wires enter the ribbon.3 to supply the sections into which the whole element is divided, such wires being denoted by 4a, lb, 40, to correspond with sections of the element, namely, A, B, and C, these sections comprising groups of consecutive branches along the length of the element I. The feed wires 4a supply current to only those branches within the section A, wires 41) to those within the section B, and wires 40 to those within the section C. In this manner each section can be heated separately as required for the work in hand, as governed 'by'a selective rheostat. Each branch element 2 is connected in parallel with the feed wires supplying that particular sector. Element wires 4 are composed of extremely ductile material and also of high resistance property and consequent high heat conductivity, and are wound around flat asbestos or other similar fibrous product in the form of cores nested together in such convenient units as to form a single layer pad of several units. The wound elements 4 are completely covered and also embedded in sheet asbestos or other similar fibrous product, such product acting both as a fire resistant and electric insulator. This entire heating element is enclosed within a sheathing 5 of flexible metal or other pressure resisting material, being securely riveted therein. The said sheathing is constructed in a plurality of sections 6a, 6b, one section slightly overlapping the next section in lap joint manner, so as to facilitate bending around both the periphery of the tire or the transverse curvature of the tire as well. The branches 2 are segmentaliy jointed as at I, the said segments being constructed in such a way as to form a continuous flexible plate containing the several elements. These segments are built up by riveting at 8 to a continuous strip 9 a series of sheathing plates at intervals, and covering the gaps between the said plates with slidable cover plates overlapping the ends of the fixed plates so that bending of the whole pad is facilitated by the sliding action of the overlapping plates on the fixed plates. The cover plates are also riveted in their centers as at III to the strip 9. A complete pad I is placeable both on the outside of a tire or cover as well as on the obverse face of the same, at the area to be treated, in such im proved manner as to thoroughly doctor that area of the tire or cover at both faces and thus attacking the material to be vulcanized in the most efficient and positive manner.

The mechanical means of attaining the proper disposition of the elements is shown clearly in Fig. 6, where II is a trough to contain a tire I2 which trough is of such shape to fit the con vex curvature of the inserted tire. A pressure form I3 is disposed within the trough II to contact the inner concave and curved face of the tire, said formbeing pressure controlled by rotat- -'able thrust bolts I4 (one only of which is shown in the illustration). The pressure is produced by the passage of the threaded'portion of the said bolt(s) I4 through a threaded hole in a fixed bar bridging the top of the walls of the trough I I as shown by l5. The bolts I4 are rotated by handles I6 at their upper ends, and convey pressure to the forms where needed. Toggle bars I! are inserted to distribute an even pressure to the upturned horned ends I8 of the forms I3, said bars being pivotally connected to a toggle bearer block I9, which block travels up and down with the bolt I4 when the same is rotated. The said means for producing the necessary pressure to the tire may vary in specific design, the illustration showing a typical form of trough which has its base split longitudinally at 20 with bolts 2| threaded into the base block of the trough so that the walls of the trough may be separated or closed together to accommodate the different types and sizes of tires under repair. A plurality of these pressure units is necessary to effect the required evenness of pressure along the strip of tire under treatment. The toggle bars I! are pivoted by pin connections 22 to the bearer block I9 as shown in Fig. 9. The said circular block I9 has grooves 23 cut diametrically in which the pivotal end of each toggle bar I! is inserted and pinned. A solid or fitted collar 24 forms part of the bolt I4 which collar is positioned so as to rest on top of the block I9. A thrust ball bearing 25 is inserted in a housing formed in the top face of the block I9 so that when the bolt I4 is rotated the block will not rotate. Bolt I4 passes through and is free to rotate within the block I9. The toggle bars I! fit loosely at their lower ends into cupped lugs 26 attached to the horned ends I8 of the form I3, the ends of the bars being threaded and burrs or nuts 27 screwed thereon so that pressure is transmitted through the contact of these burrs and the top faces of the said lugs. that they make contact slightly before the bolt I4 touches the form I3 within a cupped lug 28 attached to the middle of the said form I3 placed to receive the end of the bolt I4. Pressure is actually delivered to the bolt I4 through a spring 29 enclosed in a cylinder 30, which latter is disposed between the bridge bar I and a threaded collar. 3| mounted on the bolt I4 below the bridge bar. The cylinder 30 is keyed against rotation to the bridge bar I5 as shown at 32. A vertical slot 33 is cut in the cylinder wall to receive a pointer 34 to register pressure applied on a graduated scale paralleling the said slot. This pointer projects from the said screw collar 3| and therefore prevents the collar from rotating. The enclosed spring 29 is compressed between the collar 3| and the under sideof the The adjustment of these nuts 21 is suchbridge bar I5 within the cylinder 30. As the collar is screwed up the bolt I4 transmits pressure to the form I3, which pressure is registered on the scale by the pointer 34. A plate is inserted between the two halves of the trough I I in the floor as at 20 with clearance holes for the bolts 2| to pass through to withstand the pressure when the space is greater than that illustrated.

In Fig. 7 is illustrated the mechanical means for applying these heating elements for the treatment of tubes and other flat objects by elec tric vulcanizing, provision being made for vulcanizing around the valve stem of a tube with an electric element of circular construction as shown at 35. A top electric element 36 and a bottom electric element 37 are attached to compressing forms 38 and 39 respectively, the said elements being of identical construction to those previously described for tire vulcanizing, except that they are not necessarily built in sections, and would be single electric circuit elements, and are not necessarily a series of unit elements connected electrically in parallel. Element 36 is protected by a plate 40 and element 31 is protected by a plate 4I, each element being slidably removable with their mounting forms from the stand supporting them. 42 is an alternative type of element mounted on a plate 43 for use when flat pieces of material require vulcanizing. A suitably shaped top compressing plate is shown in broken lines at 44.

The electrical connections are as follows: Twopole leads 4a, 4b, 40, etc., run throughout the center ribbon 3 of the pad I longitudinally to supply in separate circuits the sections A, B, and C. Each of the said sections is electrically controlled separately by a selector switch which is not shown. The heating elements 4 in the branches 2 are run in parallel oil the supply leads 4a, 4b, and 40. A heat regulating rheostat is included within the electric circuits in'order to control and vary the amount of heat necessary for vulcanizing purposes. This may be of any standard type of resistance control.

A look bar 45 keeps the walls of the trough II in position against the action of the bridge piece I5. These two members must be changed for different widths of tire in the trough.

In order to accommodate the curved tire and element fillet blocks 46 are inserted in the lower corners longitudinally in the bottom of the trough, upon these the outside element Ia is laid, then a pressure plate 41 of the same shape as the outer face of the tire is placed upon the element Ia. This plate is grooved on its outer convex face as shown in Fig. 8, the grooves 48 being shaped to receive the branches 2 of the element pad I in order to prevent crushing the elements out of shape when under pressure. The inner face or concave surface of this plate 48 is also grooved by moulding to accommodate the tread of the tire as at 49. The tire cover is placed upon this plate 41 within the trough II. Next a plate 50 rests on the inner face of the tire, and the inner element II) is fitted thereon. On the convex face of the pressure form I3 contacting this element Ib are grooves similar to those illustrated by 48 in Fig. 8, which grooves are also toaccommodate the branches 2 of the element pad I, the purpose of these grooves being to avoid disruption of the elements under pressure.

Wherewith rubber tires and tubes have been mentioned for treatment in this specification it is to be understood that any goods are included that are amenable to the action of heat for vulcanizing, and that the word tube refers to the inner pneumatic element of a tire, and that the word tire refers to the outer enclosing casing.

In the selector plug switch (Fig. 10) ii is a block of Bakelite or other insulating composition mounted on a base plate 52, the said block having the same number of pairs of plug holes I! as there are couples of circuits la, lb, and 4c in the vulcanizing element I. Within said plug holes are split conductor rings 54 set in the said plug holes 53, each pair of rings forming single pole plug terminals in an element circuit 4, etc. One half of each said split ring is connected to single pole bus bars 55 on the main supply conductor, and the other halt of each split ring is connected to one side or.conductor wire in the element I, and the other side or conductor wire in the element 8. Two plugs 56 are inserted in the contact plug rings 54 as required to complete an element circuit Ha, lb-Jb, and 4c4c.

A current regulator 51 is shown in Fig. 11, this being of a conventional type having single pole terminals 58 and 59, also a series of arcular contact stops in bridging a length of resistance wire I at predetermined points for eflective heat variation purposes. A radially pivoted arm 62 is slidably operated by a handle 63 serving as an adjustable contact maker in series between the main terminals 58 and 59 through and bridging the wire 6|.

I am fully aware that electric heating elements have been invented for use in connection with vulcanizing, especial attention having been paid to Canadian Patent No. 335,939, but in view even of such I desire to secure Letters Patent for my improvements by claiming the following:

In an electric vulcanizing device of the type described, an electrically heated flexible pad element having tributary element branches, said branches containing flexible electric heat producing conductor wires for placement on the outer and inner or obverse faces of tires, tubes, or other articles to be vulcanized, means for fireprooflng and insulating said conductor wires to withstand pressure, means for directing electric current individually to the wires of certain of the said branches to produce the necessary heat in any particular area of the article to be treated, and flexible jointed pressure resisting sheathing encasing said fireproofed and insulated conductor wires, all in combination.

ALBERT HOVING. 

